Characterising post-COVID syndrome more than 6 months after acute infection in adults; prospective longitudinal cohort study, England

Abstract

AbstractBackgroundMost individuals with COVID-19 will recover without sequelae, but some will develop long- term multi-system impairments. The definition, duration, prevalence and symptoms associated with long COVID, however, have not been established.MethodsPublic Health England (PHE) initiated longitudinal surveillance of clinical and non-clinical healthcare workers for monthly blood sampling for SARS-CoV-2 antibodies in March 2020. Eight months after enrolment, participants completed an online questionnaire including 72 symptoms in the preceding month. Symptomatic mild-to-moderate cases with confirmed COVID-19 were compared with asymptomatic, seronegative controls. Multivariable logistic regression was used to identify independent symptoms associated with long COVID.ResultsAll 2,147 participants were contacted and 1,671 (77.8%) completed the questionnaire, including 140 (8.4%) cases and 1,160 controls. At a median of 7.5 (IQR 7.1-7.8) months after infection, 20 cases (14.3%) had ongoing (4/140, 2.9%) or episodic (16/140, 11.4%) symptoms. We identified three clusters of symptoms associated with long COVID, those affecting the sensory (ageusia, anosmia, loss of appetite and blurred vision), neurological (forgetfulness, short-term memory loss and confusion/brain fog) and cardiorespiratory (chest tightness/pain, unusual fatigue, breathlessness after minimal exertion/at rest, palpitations) systems. The sensory cluster had the highest association with being a case (aOR 5.25, 95% CI 3.45-8.01). Dermatological, gynaecological, gastrointestinal or mental health symptoms were not significantly different between cases and controls.ConclusionsMost persistent symptoms reported following mild COVID-19 were equally common in cases and controls. While all three clusters identified had a strong association with previous COVID-19 infection, the sensory cluster had the highest specificity and strength of association.Key pointsCompared to controls, we identified three clusters of symptoms affecting the sensory, neurological and cardiorespiratory systems that were more prevalent among cases. Notably, gastrointestinal and dermatological symptoms and symptoms related to mental health were as prevalent among cases as controls.